1. Technical Field
The disclosed embodiments relate in general to a radar wave sensing apparatus and a method thereof.
2. Description of the Related Art
As the high precision requirements expected by the machine tools are getting higher and higher, the requirements related to the unbalance and vibration of a rotation element also become crucial. Examples of the sensors used for measuring the vibration of a rotation element include the accelerometer, the speedometer, the force sensor and the acceleration sensing apparatus used in micro electro mechanical system (MEMS). Examples of the sensing apparatuses used for measuring the eccentricity of a rotation element include electronic displacement meter and dial indicator. Examples of the sensors used for measuring the vibration on a rotation surface of a rotation element in a non-contact manner include the laser interferometer, the triangulation laser displacement meter, the eddy-current displacement meter and the inductor current displacement meter.
The accelerometer is a most commonly used tool for measuring the unbalance generated in the measurement of the rotation element (that is, the rotator) of a machine tool. The accelerometer measures the vibration on a surface of a rotation element in an indirect manner. The dial gauge can only be used in the measurement of static deflection. If the dial gauge is used for measuring an object under high-speed rotation, the contact force may cause scratch on the surface and errors to the measurements of dynamic vibration of an object under rotation. Furthermore, measuring a rotation element in a contact manner may easily damage the surface of the rotation element and the sensor itself. Despite that the laser interferometer and the current displacement meter would be better choices, the laser interferometer is very expensive in cost and the current displacement meter is huge in size and have to take many factors into consideration in terms of use.